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Abstract:

The invention relates to a pneumatically and/or electromechanically
actuable commercial vehicle disc brake having a brake disc, a brake
calliper, a brake application shaft which can be actuated by means of a
pivoting lever and lies transversely with respect to a rotational axis of
the brake disc, an adjusting device which is arranged at least partially
within an inner space of the brake calliper, and a first sealing device
for sealing an annular space which is delimited by the inner wall of a
through opening of the brake calliper and a device which extends through
the through opening. According to the invention, a holding device, which
holds a second sealing device for sealing the annular space at least
partially, and a third sealing device are provided, which sealing device
bears against the holding device for sealing the annular space at least
partially.

Claims:

1. A pneumatically and/or electromechanically actuable commercial vehicle
disc brake havinga brake disc,a brake calliper,a brake application shaft
which can be actuated by means of a pivoting lever and lies transversely
with respect to a rotational axis of the brake disc,an adjusting device
which is arranged at least partially within an inner space of the brake
calliper, anda first sealing device for sealing an annular space which is
delimited by the inner wall of a through opening of the brake calliper
and a device which extends through the through opening,characterized in
thatit comprises a holding device that holds a second sealing device for
at least partially sealing the annular space anda third sealing device
that bears against the holding device for at least partially sealing the
annular space.

2. The brake according to claim 1, characterized in that the through
opening is a functional opening.

3. The brake according to claim 1, characterized in that the device that
extends through the through opening comprises a pressure collar and/or an
adjusting spindle.

4. The brake according to claim 1, characterized in that the holding
device has a sleeve design.

5. The brake according to claim 1, characterized in that the second
sealing device has a T-shaped cross section.

6. The brake according to claim 1, characterized in that the holding
device couples the second the second sealing device in circumferential
and/or axial direction of the brake with the device that extends through
the through opening.

7. The brake according to claim 1, characterized in that the device that
extends through the through opening and/or the adjusting device
comprise(s) a male thread that cuts into the second sealing device at the
transition from a first to a second operating state.

8. The brake according to claim 7, characterized in that that portion of
the second sealing device into which the male thread cuts is designed
and/or formed in such a way that it will not twist as a result of
relative movement with respect to the male thread.

9. The brake according to claim 1, characterized in that the holding
device, the second sealing device and at least a portion of the device
that extends through the through opening, in particular a pressure
collar, form a prefabricated module.

10. The brake according to claim 9, characterized in that the module is
prefabricated by compression molding.

11. The brake according to claim 1, characterized in that it comprises a
grease reservoir delimited by the second sealing device.

12. The brake according to claim 1, characterized in that the third
sealing device flatly rests against a portion of the inner wall of the
through opening.

13. The brake according to claim 1, characterized in that the third
sealing device comprises a portion protruding radially outwards beyond
the inner wall of the through opening.

14. The brake according to claim 1, characterized in that the third
sealing device is annular.

15. The brake according to claim 1, characterized in that an inner
diameter of the third sealing device is smaller in idle state than an
outer diameter of the holding device.

16. The brake according to claim 1, characterized in that the third
sealing device comprises a sealing lip extending radially inwards.

17. The brake according to claim 1, characterized in that the third
sealing device is at least in some sections elastic.

18. The brake according to claim 1, characterized in that the third
sealing device comprises a reinforcement.

19. The brake according to claim 1, characterized in that the second
sealing device, the third sealing device and/or the holding device is/are
rotationally symmetrical.

20. The brake according to claim 1, characterized in that a surface
portion of the holding device against which the third sealing device
rests has a smooth finish that enhances a tight seal.

21. The brake according to claim 1, characterized in that the brake
application shaft rests on a pressure block on its brake application end.

22. The brake according to claim 1, characterized in that the adjusting
device comprises an adjusting nut and an adjusting spindle.

23. The brake according to claim 1, characterized in that the through
opening is provided on a lid of the brake calliper.

24. The brake according to claim 23, characterized in that the lid forms a
prefabricated module with the third sealing device.

25. A pneumatically and/or electromechanically actuable commercial vehicle
disc brake having a brake disc,a brake calliper,a brake application shaft
which can be actuated by means of a pivoting lever and lies transversely
with respect to a rotational axis of the brake disc,an adjusting device
which is arranged at least partially within an inner space of the brake
calliper,a first sealing device for sealing an annular space which is
delimited by the inner wall of a through opening of the brake calliper
and a device which extends through the through opening,a holding device
that holds a second sealing device for at least partially sealing the
annular space, anda third sealing device that bears against the holding
device for at least partially sealing the annular space,characterized in
thatthe device extending through the through opening comprises a pressure
collar of an adjusting nut andthe holding device, the second sealing
device, and the pressure collar form a prefabricated module.

Description:

[0004]a brake application shaft which can be actuated by means of a
pivoting lever and lies transversely with respect to a rotational axis of
the brake disc,

[0005]an adjusting device which is arranged at least partially within an
inner space of the brake calliper, and

[0006]a first sealing device for sealing an annular space which is
delimited by the inner wall of a through opening of the brake calliper
and a device which extends through the through opening.

[0007]Disc brakes of the above type are known, for example, from DE 103 56
801 B3. The first sealing device is formed by an elastic protective cap
that has the form of a bellows-type sleeve that extends as a result of
screwing out a pressure spindle of the adjusting device. In the known
disc brake, it represents the only device for sealing the annular space
and thus the interior of the brake calliper and the brake application and
adjusting components it contains from external influences of any kind.
The sealing device itself is exposed to the most varied external
influences. These include mechanical influences such as gravel impact or
inappropriate handling when servicing the brake. There are also thermal
influences since the brake pad and brake disc are in the immediate
vicinity. These influences can damage or even destroy the bellows-type
sleeve. If the bellows-type sleeve is damaged and destroyed, however, all
brake components will be exposed to environmental influences without
protection so that the brake function may be impaired or even fail
completely.

[0008]It is the problem of this invention to improve the disc brake
according to DE 103 56 801 B3 in such a way that the brake interior and
the components housed in it are effectively protected and that both the
first installation of the brake and any later replacement of components
are simple.

[0009]According to the invention, this problem is solved in a disc brake
of the type described above by a holding device that holds a second
sealing device for sealing the annular space at least partially.
Furthermore, a third sealing device is provided that bears against the
holding device for sealing the annular space at least partially.

[0010]Providing a second sealing device makes the entire sealing system
redundant and thus more effective. The holding device that holds the
second sealing device simplifies the first installation of the brake as
well as the replacement of brake parts. The third sealing device further
increases redundancy and thus the effectiveness of the sealing system.
The holding device adds two functions: it holds the second sealing device
and it interacts with the third sealing device to seal the annular space
since the third sealing device bears against the holding device.
Therefore the holding device is of special importance for the sealing
system.

[0011]According to the invention, the through opening is a functional
opening. In other words, at least one brake element that contributes to
the functioning of the brake extends through the through opening. It can
be the pressure collar of an adjusting nut and/or a pressure piston that
may also be designed as a pressure spindle.

[0012]According to the invention, the device that extends through the
through opening comprises a pressure collar and/or an adjusting spindle.

[0013]In a preferred embodiment of the invention, the holding device has a
sleeve design. This results in particularly easy handling during first
installation and part replacement.

[0014]The second sealing device preferably has a T-shaped cross section.
The part that corresponds to the vertical bar of the "T" is preferably
used for particularly reliable sealing of annular space while the
transverse bar is used to fasten the sealing device within the brake.

[0015]According to the invention, the holding device also preferably
couples the second sealing device in circumferential and/or axial
direction of the brake with the device that extends through the through
opening. It thus turns with the pressure collar, for example, when the
brake is adjusted.

[0016]According to another preferred embodiment of the invention, the
device that extends through the through opening and/or the adjusting
device comprise(s) a male thread that cuts into the second sealing device
at the transition from a first to a second operating state.

[0017]For example, the male thread will cut into the second sealing device
on first contact, that is, at the transition from new to another
operating state. This causes the sealing device to come to rest against
the flanks of the male thread. The same effect occurs if a multi-start
thread is used. This makes automated assembly processes simpler or makes
them work at all.

[0018]According to the invention, the portion of the sealing device that
engages in the male thread is designed and/or formed in such a way that
it will not twist as a result of relative movement of the male thread.

[0019]Appropriate dimensioning (radial length) of the relevant part
(vertical bar of the "T") will particularly contribute to this.

[0020]The holding device, the second sealing device, and at least one part
of the device that extends through the through opening, especially the
pressure collar, make up a prefabricated module according to yet another
preferred embodiment of the invention. This simplifies first installation
of the brake and part replacement.

[0021]It is further preferred that the module is prefabricated by
compression molding. This also makes the manufacturing and/or replacement
process easier.

[0022]According to the invention, it is further preferred to provide a
grease reservoir that is delimited by the second sealing device. Other
parts that can form the perimeter of the grease reservoir include a
pressure block and/or a pressure spindle with a male thread. This can
prevent friction coefficient variations for parts that glide on one
another.

[0023]According to the invention, the third sealing device flatly rests
against a portion of the inner wall of the through opening. This improves
the reliability of the seal.

[0024]According to the invention, the third sealing device preferably
comprises a portion protruding radially outwards beyond the inner wall of
the through opening. This fastens it in axial direction of the brake.

[0025]The third sealing device of the invention is also preferably
annular. This makes it fit to the annular space.

[0026]According to the invention, an inner diameter of the third sealing
device is smaller in idle state than an outer diameter of the holding
device.

In the assembled state, the third sealing device will therefore come to
rest against the outer shell of the holding device, which increases the
sealing effect.

[0027]According to the invention, the third sealing device preferably
comprises a sealing lip stretching radially inwards. The main purpose of
this sealing lip is to rest against the outer shell of the holding device
for effective sealing of the annular space.

[0028]According to the invention, it is further preferred that the third
sealing device is at least in some sections elastic. The elastic
restoring force can be used for better sealing.

[0029]According to the invention, the third sealing device can comprise a
reinforcement, especially in the form of an embedded metal ring. It is
used in particular for protective and stabilizing purposes and thus also
supports the holding and sealing function on the outer surface of the
through opening.

[0030]It is preferred according to the invention that the second sealing
device, the third sealing device, and/or the holding device have a
rotationally symmetric design. This means that they do not have to be
brought into a specific rotational position during assembly.

[0031]The surface area of the holding device against which the third
sealing device rests has a smooth finish that promotes the sealing
effect. In particular, the holding device is made of metal. It takes much
less effort to give the holding device a particularly smooth surface
than, for example, to give the pressure collar an according design. The
smooth surface is particularly advantageous in embodiments in which the
third sealing device is moved relative to the surface it interacts with
during brake operation, i.e. the holding device.

[0032]In the disc brake according to the invention, the brake application
shaft is advantageously supported by a pressure block on its brake
application end.

[0033]Furthermore, the adjusting device advantageously comprises an
adjusting nut and an adjusting spindle.

[0034]The through opening can be provided on the main body of the brake
calliper or on the lid of the brake calliper.

[0035]It is preferred that the lid and the third sealing device form a
prefabricated module. When it is installed, the third sealing device
moves onto the holding device, which makes installation even simpler.

[0036]Finally, the invention preferably provides a pneumatically and/or
electromechanically actuable commercial vehicle disc brake having a brake
disc, a brake calliper, a brake application shaft which can be actuated
by means of a pivoting lever and lies transversely with respect to a
rotational axis of the brake disc, an adjusting device which is arranged
at least partially within an inner space of the brake calliper, a first
sealing device for sealing an annular space which is delimited by the
inner wall of a through opening of the brake calliper and a device which
extends through the through opening, a holding device that holds a second
sealing device for sealing the annular space at least partially, and a
third sealing device that bears against the holding device for sealing
the annular space at least partially, characterized in that the device
that extends through the through opening comprises a pressure collar of
an adjusting nut and in that the holding device, the second sealing
device, and the pressure collar form a prefabricated module.

[0037]The invention will be explained in more detail using a preferred
embodiment and with reference to the enclosed figures. Wherein:

[0038]FIG. 1 shows a schematic sectional view of an embodiment of the disc
brake according to the invention,

[0039]FIG. 2 shows another schematic sectional view of the embodiment
according to FIG. 1,

[0040]FIG. 3 shows a schematic partial sectional perspective view of a
part of the embodiment according to FIG. 1 in its initial position; and

[0041]FIG. 4 shows another schematic partial sectional perspective view of
a part of the embodiment according to FIG. 1 with a partly screwed out
pressure spindle.

[0042]The brake shown in the figure is a commercial vehicle brake having a
brake calliper 2 that includes the brake disc 1 and supports a brake
application shaft 4 which can be actuated by means of a pivoting lever 3
and lies transversely with respect to a rotational axis 1A of the brake
disc 1. The brake application shaft 4 interacts with a splined pressure
block 5 that extends transversely with respect to the brake disc 1. The
pressure block 5 comprises a through opening 6 which houses, as part of
the adjusting device, a rotatable adjusting nut 7 having a pressure
collar 8 facing the brake disc 1. A pressure spindle 9 with a male thread
9A is screwed into said adjusting nut 7 and cannot pivot about the
rotational axis 1A. When the brake is actuated, it presses against a
brake pad 10 on the brake application side. The brake application lever
3, the brake application shaft 4, the pressure block 5, the adjusting nut
7, and the pressure spindle 9 are (at least partially) housed in an inner
space 2A of the brake calliper 2. The brake calliper 2 comprises a
functional opening facing towards the brake disc 1 into or through which
the pressure collar 8 of the adjusting nut 7 and the pressure spindle 9
extend. An annular space 11A is located between the inner wall of the
through opening 11 of the calliper 2 and the pressure collar 8 of the
adjusting nut or the pressure spindle 9, respectively. An elastic
protective cap in the form of a bellows-type sleeve 12 is used for
sealing this annular space. It is on one end attached to the brake
calliper 2 or, according to FIGS. 3 and 4, to a lid 2.1 that can be
attached to the brake calliper, and on the other end to the portion 13 of
the pressure spindle 9 that faces the brake disc 1. The pressure block 5
rests on the brake application side of the pressure collar.

[0043]The section of the pressure collar 8 of the adjusting nut 7 that
extends into the functional opening 11 is used for form-fitting fastening
of a sleeve body 14 that encompasses the axial and radial pressure collar
sections; said sleeve body is used as a sealing surface against a seal 15
that seals the inner space 2A and at the same time for holding a seal 16
that protects the male thread 9A of the pressure spindle 9. The seal 15
is located in the radially outer part of the annular space 11A, the seal
16 in its radially inner part.

[0044]In other words, the pressure collar 8 with the sealing and fastening
sleeve in form of the sleeve body 14 attached to it is of special
importance for the design and arrangement of the redundant sealing system
according to the invention.

[0045]The seal 15 is made of an elastic material. It is configured in such
a way that it encompasses and seals the functional opening 11 across its
entire surface and on both sides when installed. On the side facing the
brake pad 10, a metal ring 15.1 embedded in the seal material is provided
that has the shape of an "L" in the embodiment shown. It has a protective
and stabilizing function. In addition, it makes installation simpler,
especially automated installation. A torus 152 that protrudes in radial
direction beyond the functional opening 11 is provided on the side facing
the inner space 2A. This holds the seal 15 reliably on the functional
opening 11.

[0046]The seal 15 has an elastic annular space lip 15.3 in radial inward
direction. Its inner diameter is smaller than the outer diameter of the
sleeve body 14. In other words, the radial extension of the annular space
lip 15.3 is so dimensioned that it completely surrounds the sleeve body
14. In assembled condition, it rests with its entire area against the
outer shell of the sleeve body 14. Due to its elasticity, this stationary
annular space seal can compensate axial, radial, and rotational movements
performed by the pressure collar 8 of the adjusting nut 7 with the sleeve
body 14 during braking and brake adjustment without losing sealing
capacity.

[0047]The shell surface of the holding sleeve that is preferably made of
metal and against which the annular space lip 15.3 sits tightly in
assembled condition is very smooth. The smooth finish of this shell
surface can be achieved much easier than for other brake elements such as
the pressure collar 8. The holding sleeve 14 provides an optimum sealing
surface and reliable multiple protection of the inner space 2A of the
disc brake in interaction with the elastic (annular space) seal 15. It is
also used for holding the seal 16 in the embodiment of the invention
shown in the figure. It is thus multifunctional.

[0048]The elastic seal 16 is provided for effective protection of the male
thread 9A and the spindle drive formed by the adjusting nut 7 and the
pressure spindle 9. It is fastened in axial and radial position by the
sleeve body 14 on the front end of the pressure collar 8 that faces the
brake pad 10. It turns with the adjusting nut 7. This is why it has a
T-shaped cross section. This results in bulge sections 16.1, 16.2 that
provide an all-round seal on both sides of the outer shell in the
direction of the pressure collar 8 and the sleeve body 14.

[0049]The sealing area/lip 16.3 that has a very slim design and extends in
the direction of the male thread 9A of the non-pivoting pressure spindle
9. This section of the seal 16 is made of such material and dimensioned
in such a way that the male thread 9A cuts into it on first contact with
the start of the thread. In this way, the inner sealing surface of the
seal 16 automatically comes to rest against the thread flanks. This
produces optimum thread sealing even in radial direction, which is highly
effective for multi-start threads. This design is particularly
advantageous with respect to automated assembly.

[0050]Another advantage results from the comparatively large contact area
of the section of the sleeve body 14 that is used as a holder and the
sealing surface/lip 16.3 in the direction of the thread. This makes this
section comparatively large in area, which is why it will not twist if
there are movements relative to the male thread 9A.

[0051]The seal 16 is compression molded with the holding sleeve 14 and the
pressure collar 8 as a prefabricated module that will then be completed
with the remaining components. This makes the installation process
considerably simpler.

[0052]Since the seals 15 and 16 do not or just slightly change their
installation positions and are approximately on top of one another in
radial direction, the very narrow installation spaces in the brake are
utilized to an optimum extent. Said sealing and bearing/holding
components are rotationally symmetrical. This means that no special
embodiments have to be brought into a specific installation position.

[0053]The axial installation length of the sleeve body 14 is so
dimensioned that there is no risk of crushing the seal 16 when the seal
16 is inserted first and then compression molded onto the pressure collar
8. This is ensured by its closed length with respect to the end of the
pressure collar when the module is assembled. A grease reservoir 17 is
formed by the male thread 9A, the pressure collar 8, and the seal 16.
This is to prevent variations of the friction coefficient if the said
elements move relative to one another.

[0054]The functional opening 11 is placed on the main body of the brake
calliper 2 in the embodiment shown. It can also be provided on a lid of
the brake calliper 2.

[0055]The brake shown in the figure is actuated by swiveling the pivoting
lever 3 if a braking process is initiated, for example, via an actuating
device flanged onto the brake calliper 2. Movement towards the brake pad
10 occurs involving the pressure block 5 that supports at least one
adjusting nut/pressure spindle arrangement. When the brake is released, a
(pressure) spring system moves the entire brake application device back
to its initial position. Thus the annular space lip 15.3 will slide
across the outside area of the sleeve body 14 when there are purely axial
movements. If required adjustment movements occur via the adjusting
device not shown here (see FIG. 4), the adjusting nut 7 rotates and the
pressure spindle 9 is screwed out. The male thread 9A turns with respect
to the seal 16 held on the adjusting nut 7 or the pressure collar 8,
respectively, or relative to the sealing surface/lip 16.3 resting against
the flanks of the thread, respectively. Even if the bellows-type sleeve
12 were damaged, the multiple seals effectively protect the inner space
2A of the brake calliper 2 and in particular the spindle drive. The
bellows-type sleeve 12 can than be replaced in the conventional way
during a later brake service. This applies similarly to the seal 15, if
required. As can especially be seen in FIG. 4, the seals 15 and 16 do not
change their positions although the pressure spindle 9 is screwed out of
the adjusting nut 7 due to adjusting movements.

[0056]As can be seen from FIGS. 3 and 4, the calliper 2 is closed with a
lid 2.1 on the side of the brake disc. Even if this cannot be seen in the
figure, the lid 2.1 can for example be screwed onto the main body of the
calliper 2. The lid 2.1 for simpler installation with the third sealing
device 15 before it is fastened to the calliper 2, e.g. by means of a
screwed connection. When the lid 2.1 is screwed or fastened to the
calliper 2, the "tilted" third sealing device 15 moves onto the holding
device 14. The sealing function is particularly effective if the sealing
device 15 is or remains (permanently) "tilted" facing outwards in all
operating states of the brake.

[0057]Although the embodiment shown in the figures is a single-spindle
brake, the invention can also be applied to two- or multi-spindle brakes
because these brakes also comprise functional openings towards a brake
pad or brake disc through which functional elements extend.

[0058]The characteristics disclosed in the above description, the claims
and the figures can be relevant both individually and in combination for
implementing the various embodiments of the invention.

Patent applications by Wolfgang Falter, Heidelberg DE

Patent applications by WABCO RADBREMSEN GMBH

Patent applications in class With means to adjust for wear of brake

Patent applications in all subclasses With means to adjust for wear of brake